title: Restriction in IgM expression. III. Affinity analysis of monoclonal anti-lactose antibodies.
abstract: A clonal analysis has been made of the murine BALB/C response to lactose-containing immunogens with respect to the affinity restriction in IgM expression. Monoclonal IgM and IgG antibodies were prepared from antilactosyl hybridomas generated from mice immunized with p-aminophenyl-beta-lactoside (PAPL) coupled to BGG or with a vaccine of Streptococcus faecalis (Strain N). Association constants for the binding of monovalent derivatives of PAPL were measured by quenching fluorescence. These derivatives carried a probe (2,4-dinitrophenyl or 1-dimethylaminonaphthalene-5-sulfonyl) that served to quench the protein fluorescence when the ligand was complexed with the protein. The central finding was that with both immunogens a restriction in the affinity of IgM was demonstrated since the highest values exhibited by IgG antibody exceeded by at least a factor of 50 the highest comparable values of the association constants for IgM antibody. It is suggested that the hypothesis of germ-line restriction, previously proposed as the basis for the affinity restriction of IgM, may also be applicable to the T cell receptor since its distinctive properties parallel those of IgM antibody.
mesh_terms: D000818:Animals; D000906:Antibodies; D000911:Antibodies, Monoclonal; D000915:Antibody Affinity; D005260:Female; D006027:Glycosides / Q000276:immunology; D006822:Hybrid Cells / Q000276:immunology; D007075:Immunoglobulin M; D007785:Lactose / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011817:Rabbits
chemical_list: D000906:Antibodies; D000911:Antibodies, Monoclonal; D006027:Glycosides; D007075:Immunoglobulin M; C029976:4-aminophenyl beta-lactoside; D007785:Lactose